Casas David, Barriga-Carrasco Manuel D, Rubio Juan
E.T.S.I. Industriales, Universidad de Castilla-La Mancha, E-13071 Ciudad Real, Spain.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Sep;88(3):033102. doi: 10.1103/PhysRevE.88.033102. Epub 2013 Sep 9.
In this work, proton and deuteron stopping due to free and bound electrons in partially ionized plasma targets is evaluated. The stopping of target free electrons is calculated using the dielectric formalism, well described in our previous works. In the case of target bound electrons, a short expression to calculate their contribution to the stopping is used, where mean excitation energies are obtained by means of the Hartree-Fock method. Experiments with different kinds of plasmas are analyzed. For LiH plasma, estimated plasma stopping fits experimental data very well, within the error bars, recognizing the well-known enhanced plasma stopping. In the case of CH_{2} plasma, we obtain, from estimated ionization, that total stopping power increases when target electron density does. Our estimations are very similar to experimental data which show the same behavior with target free and bound electron density. Finally, in Al plasma, we compare directly our calculations with experimental data finding a very close agreement, where both stoppings have the same dependence on target ionicity. All these comparisons verify our theoretical model which estimates the proton or deuteron energy loss in partially ionized plasmas.
在这项工作中,评估了部分电离等离子体靶中自由电子和束缚电子导致的质子和氘核阻止本领。靶自由电子的阻止本领使用介电形式理论进行计算,这在我们之前的工作中有详细描述。对于靶束缚电子的情况,使用了一个简短的表达式来计算它们对阻止本领的贡献,其中平均激发能通过哈特里 - 福克方法获得。分析了不同类型等离子体的实验。对于氢化锂(LiH)等离子体,在误差范围内,估计的等离子体阻止本领与实验数据拟合得非常好,认识到了众所周知的增强等离子体阻止效应。对于二氢化碳(CH₂)等离子体,从估计的电离情况来看,当靶电子密度增加时,总阻止本领也会增加。我们的估计与实验数据非常相似,实验数据显示出与靶自由电子和束缚电子密度相同的行为。最后,在铝(Al)等离子体中,我们将计算结果与实验数据直接比较,发现两者非常吻合,其中两种阻止本领对靶离子性具有相同的依赖性。所有这些比较都验证了我们估计部分电离等离子体中质子或氘核能量损失的理论模型。